MELBOURNE, March 22 (Reuters) - Commodity giant Glencore on Friday said it had suspended operations at its McArthur River zinc mine in northern Australia as a cyclone approaches.

Authorities have declared a state of emergency in the region as Tropical Cyclone Trevor nears, with the nation's weather bureau on Friday saying the storm was intensifying and warning of a "severe impact" ahead of landfall on Saturday morning.

At the same time, areas further west are bracing for the arrival of another cyclone, named Veronica, with key iron ore ports there being cleared.

"(The McArthur River mine) is preparing for Cyclone Trevor in line with our standard cyclone procedures," a Glencore spokesman said in a statement emailed to Reuters.

That comes after commodity giant Rio Tinto on Wednesday suspended its Weipa bauxite mining operations at the northeastern tip of the country ahead of the cyclone.

Meanwhile, Rio, BHP and Fortescue have all cleared their ships from ports ahead of Cyclone Veronica's expected landfall south of the world's largest iron ore export hub of Port Hedland on Sunday. (Reporting by Melanie Burton; Editing by Richard Pullin and Joseph Radford)